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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Sr3Ca(FeO3)4 by Materials Project

Sr3Ca(FeO3)4 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are three inequivalent Sr sites. In the first Sr site, Sr is bonded to twelve O atoms to form SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with two equivalent CaO12 cuboctahedra, faces with four equivalent SrO12 cuboctahedra, and faces with eight equivalent FeO6 octahedra. There are four shorter (2.75 Å) and eight longer (2.76 Å) Sr–O bond lengths. In the second Sr site, Sr is bonded to twelve O atoms to form SrO12 cuboctahedra that share corners with four equivalent SrO12 cuboctahedra, corners with eight equivalent CaO12 cuboctahedra, faces with six SrO12 cuboctahedra, and faces with eight equivalent FeO6 octahedra. There are four shorter (2.75 Å) and eight longer (2.78 Å) Sr–O bond lengths. In the third Sr site, Sr is bonded to twelve O atoms to form SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with two equivalent SrO12 cuboctahedra, faces with four equivalent CaO12 cuboctahedra, and faces with eight equivalent FeO6 octahedra. All Sr–O bond lengths are 2.75 Å. Ca is bonded to twelve O atoms to form CaO12 cuboctahedra that share corners with four equivalent CaO12 cuboctahedra, corners with eight equivalent SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, and faces with eight equivalent FeO6 octahedra. There are eight shorter (2.72 Å) and four longer (2.75 Å) Ca–O bond lengths. Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six equivalent FeO6 octahedra, faces with two equivalent CaO12 cuboctahedra, and faces with six SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Fe–O bond distances ranging from 1.93–1.96 Å. There are three inequivalent O sites. In the first O site, O is bonded to three Sr, one Ca, and two equivalent Fe atoms to form a mixture of distorted corner, edge, and face-sharing OSr3CaFe2 octahedra. The corner-sharing octahedra tilt angles range from 0–61°. In the second O site, O is bonded to four Sr and two equivalent Fe atoms to form distorted OSr4Fe2 octahedra that share corners with twenty OSr3CaFe2 octahedra, edges with four equivalent OSr4Fe2 octahedra, and faces with eight equivalent OSr3CaFe2 octahedra. The corner-sharing octahedra tilt angles range from 0–60°. In the third O site, O is bonded in a distorted linear geometry to two equivalent Sr, two equivalent Ca, and two equivalent Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr3Ca by Materials Project

Sr3Ca is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Sr sites. In the first Sr site, Sr is bonded to eight Sr and four equivalent Ca atoms to form SrSr8Ca4 cuboctahedra that share corners with twelve equivalent SrSr8Ca4 cuboctahedra, edges with eight equivalent CaSr12 cuboctahedra, edges with sixteen SrSr8Ca4 cuboctahedra, faces with four equivalent CaSr12 cuboctahedra, and faces with fourteen SrSr8Ca4 cuboctahedra. There are four shorter (4.17 Å) and four longer (4.18 Å) Sr–Sr bond lengths. All Sr–Ca bond lengths are 4.17 Å. In the second Sr site, Sr is bonded to eight equivalent Sr and four equivalent Ca atoms to form SrSr8Ca4 cuboctahedra that share corners with four equivalent SrSr8Ca4 cuboctahedra, corners with eight equivalent CaSr12 cuboctahedra, edges with twenty-four SrSr8Ca4 cuboctahedra, faces with six equivalent CaSr12 cuboctahedra, and faces with twelve SrSr8Ca4 cuboctahedra. All Sr–Ca bond lengths are 4.18 Å. Ca is bonded to twelve Sr atoms to form CaSr12 cuboctahedra that share corners with four equivalent CaSr12 cuboctahedra, corners with eight equivalent SrSr8Ca4 cuboctahedra, edges with eight equivalent CaSr12 cuboctahedra, edges with sixteen equivalent SrSr8Ca4 cuboctahedra, faces with four equivalent CaSr12 cuboctahedra, and faces with fourteen SrSr8Ca4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr3Ca(NCl)2 by Materials Project

Sr3Ca(NCl)2 is Caswellsilverite-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to three N3- and three Cl1- atoms to form SrN3Cl3 octahedra that share corners with six SrN3Cl3 octahedra, edges with four equivalent CaN3Cl3 octahedra, and edges with eight SrN3Cl3 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. There are two shorter (2.62 Å) and one longer (2.65 Å) Sr–N bond lengths. There are one shorter (3.06 Å) and two longer (3.09 Å) Sr–Cl bond lengths. In the second Sr2+ site, Sr2+ is bonded to three N3- and three Cl1- atoms to form distorted SrN3Cl3 octahedra that share corners with three equivalent SrN3Cl3 octahedra, corners with three equivalent CaN3Cl3 octahedra, edges with three equivalent CaN3Cl3 octahedra, and edges with nine SrN3Cl3 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. There are two shorter (2.62 Å) and one longer (2.64 Å) Sr–N bond lengths. There are two shorter (3.12 Å) and one longer (3.13 Å) Sr–Cl bond lengths. In the third Sr2+ site, Sr2+ is bonded to three N3- and three Cl1- atoms to form SrN3Cl3 octahedra that share corners with three equivalent SrN3Cl3 octahedra, corners with three equivalent CaN3Cl3 octahedra, edges with three equivalent CaN3Cl3 octahedra, and edges with nine SrN3Cl3 octahedra. The corner-sharing octahedra tilt angles range from 1–2°. There are one shorter (2.59 Å) and two longer (2.60 Å) Sr–N bond lengths. There are one shorter (3.15 Å) and two longer (3.17 Å) Sr–Cl bond lengths. Ca2+ is bonded to three N3- and three Cl1- atoms to form distorted CaN3Cl3 octahedra that share corners with six SrN3Cl3 octahedra, edges with two equivalent CaN3Cl3 octahedra, and edges with ten SrN3Cl3 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. There are one shorter (2.48 Å) and two longer (2.51 Å) Ca–N bond lengths. There are two shorter (3.11 Å) and one longer (3.15 Å) Ca–Cl bond lengths. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to four Sr2+ and two equivalent Ca2+ atoms to form NSr4Ca2 octahedra that share corners with six ClSr5Ca octahedra, edges with six NSr4Ca2 octahedra, and edges with six ClSr5Ca octahedra. The corner-sharing octahedra tilt angles range from 11–17°. In the second N3- site, N3- is bonded to five Sr2+ and one Ca2+ atom to form NSr5Ca octahedra that share corners with six ClSr5Ca octahedra, edges with six NSr4Ca2 octahedra, and edges with six ClSr5Ca octahedra. The corner-sharing octahedra tilt angles range from 12–17°. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded to five Sr2+ and one Ca2+ atom to form distorted ClSr5Ca octahedra that share corners with six NSr4Ca2 octahedra, edges with six NSr4Ca2 octahedra, and edges with six ClSr5Ca octahedra. The corner-sharing octahedra tilt angles range from 11–17°. In the second Cl1- site, Cl1- is bonded to four Sr2+ and two equivalent Ca2+ atoms to form distorted ClSr4Ca2 octahedra that share corners with six NSr4Ca2 octahedra, edges with six NSr4Ca2 octahedra, and edges with six ClSr5Ca octahedra. The corner-sharing octahedra tilt angles range from 12–17°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr3Ca(FeO3)4 by Materials Project

Sr3Ca(FeO3)4 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are three inequivalent Sr sites. In the first Sr site, Sr is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of Sr–O bond distances ranging from 2.55–3.17 Å. In the second Sr site, Sr is bonded to twelve O atoms to form distorted SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra and faces with eight FeO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.56–3.04 Å. In the third Sr site, Sr is bonded to twelve O atoms to form distorted SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra and faces with eight FeO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.56–3.05 Å. Ca is bonded in a 12-coordinate geometry to eight O atoms. There are a spread of Ca–O bond distances ranging from 2.45–2.66 Å. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six FeO6 octahedra and faces with four SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 12–19°. There are a spread of Fe–O bond distances ranging from 1.95–1.98 Å. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six FeO6 octahedra and faces with four SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 13–19°. There are a spread of Fe–O bond distances ranging from 1.95–1.98 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a 2-coordinate geometry to three Sr, one Ca, and two Fe atoms. In the second O site, O is bonded in a 6-coordinate geometry to three Sr, one Ca, and two Fe atoms. In the third O site, O is bonded in a 5-coordinate geometry to three Sr, one Ca, and two Fe atoms. In the fourth O site, O is bonded in a 5-coordinate geometry to three Sr and two Fe atoms. In the fifth O site, O is bonded in a 4-coordinate geometry to two equivalent Sr, one Ca, and two equivalent Fe atoms. In the sixth O site, O is bonded in a 6-coordinate geometry to four Sr and two equivalent Fe atoms. In the seventh O site, O is bonded in a 5-coordinate geometry to two equivalent Sr, one Ca, and two equivalent Fe atoms. In the eighth O site, O is bonded in a 6-coordinate geometry to four Sr and two equivalent Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr3Ca(CuO3)2 by Materials Project

Sr3Ca(CuO3)2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to seven O2- atoms to form distorted SrO7 pentagonal bipyramids that share corners with two equivalent SrO7 pentagonal bipyramids, corners with four equivalent CaO7 pentagonal bipyramids, edges with seven SrO7 pentagonal bipyramids, and faces with two equivalent CaO7 pentagonal bipyramids. There are a spread of Sr–O bond distances ranging from 2.49–2.68 Å. In the second Sr2+ site, Sr2+ is bonded to seven O2- atoms to form distorted SrO7 pentagonal bipyramids that share corners with two equivalent CaO7 pentagonal bipyramids, corners with four equivalent SrO7 pentagonal bipyramids, edges with two equivalent CaO7 pentagonal bipyramids, edges with five SrO7 pentagonal bipyramids, and faces with two equivalent SrO7 pentagonal bipyramids. There are a spread of Sr–O bond distances ranging from 2.48–2.64 Å. In the third Sr2+ site, Sr2+ is bonded to seven O2- atoms to form distorted SrO7 pentagonal bipyramids that share corners with six SrO7 pentagonal bipyramids, edges with three equivalent CaO7 pentagonal bipyramids, edges with four SrO7 pentagonal bipyramids, and faces with two equivalent SrO7 pentagonal bipyramids. There are a spread of Sr–O bond distances ranging from 2.47–2.64 Å. Ca2+ is bonded to seven O2- atoms to form distorted CaO7 pentagonal bipyramids that share corners with six SrO7 pentagonal bipyramids, edges with two equivalent CaO7 pentagonal bipyramids, edges with five SrO7 pentagonal bipyramids, and faces with two equivalent SrO7 pentagonal bipyramids. There are a spread of Ca–O bond distances ranging from 2.44–2.58 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.95–2.00 Å. In the second Cu2+ site, Cu2+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.93–1.97 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded to five Sr2+ and one Cu2+ atom to form OSr5Cu octahedra that share corners with eleven OSr3CaCu2 octahedra, edges with eight OSr5Cu octahedra, and faces with two equivalent OSr3CaCu2 octahedra. The corner-sharing octahedra tilt angles range from 0–62°. In the second O2- site, O2- is bonded to four Sr2+, one Ca2+, and one Cu2+ atom to form OSr4CaCu octahedra that share corners with eleven OSr3CaCu2 octahedra, edges with eight OSr5Cu octahedra, and faces with two equivalent OSr3CaCu2 octahedra. The corner-sharing octahedra tilt angles range from 0–61°. In the third O2- site, O2- is bonded to three Sr2+, two equivalent Ca2+, and one Cu2+ atom to form distorted OSr3Ca2Cu octahedra that share corners with eleven OSr3CaCu2 octahedra, edges with eight OSr5Cu octahedra, and faces with two equivalent OSr3CaCu2 octahedra. The corner-sharing octahedra tilt angles range from 0–62°. In the fourth O2- site, O2- is bonded to three Sr2+, two equivalent Ca2+, and one Cu2+ atom to form distorted OSr3Ca2Cu octahedra that share corners with eleven OSr3CaCu2 octahedra, edges with eight OSr5Cu octahedra, and faces with two equivalent OSr3CaCu2 octahedra. The corner-sharing octahedra tilt angles range from 0–62°. In the fifth O2- site, O2- is bonded to three Sr2+, one Ca2+, and two equivalent Cu2+ atoms to form OSr3CaCu2 octahedra that share corners with fourteen OSr5Cu octahedra, edges with two equivalent OSr3CaCu2 octahedra, and faces with four OSr5Cu octahedra. The corner-sharing octahedra tilt angles range from 2–62°. In the sixth O2- site, O2- is bonded to three Sr2+, one Ca2+, and two equivalent Cu2+ atoms to form OSr3CaCu2 octahedra that share corners with fourteen OSr5Cu octahedra, edges with two equivalent OSr3CaCu2 octahedra, and faces with four OSr4CaCu octahedra. The corner-sharing octahedra tilt angles range from 3–62°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr3Ca by Materials Project

Sr3Ca is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Sr is bonded to eight equivalent Sr and four equivalent Ca atoms to form SrSr8Ca4 cuboctahedra that share corners with twelve equivalent SrSr8Ca4 cuboctahedra, edges with eight equivalent CaSr12 cuboctahedra, edges with sixteen equivalent SrSr8Ca4 cuboctahedra, faces with four equivalent CaSr12 cuboctahedra, and faces with fourteen equivalent SrSr8Ca4 cuboctahedra. All Sr–Sr bond lengths are 4.16 Å. All Sr–Ca bond lengths are 4.16 Å. Ca is bonded to twelve equivalent Sr atoms to form CaSr12 cuboctahedra that share corners with twelve equivalent CaSr12 cuboctahedra, edges with twenty-four equivalent SrSr8Ca4 cuboctahedra, faces with six equivalent CaSr12 cuboctahedra, and faces with twelve equivalent SrSr8Ca4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr3Ca(FeO3)4 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
NASA NTRS2004

Nuclear Microprobe using Elastic Recoil Detection (ERD) for Hydrogen Profiling in High Temperature Protonic Conductors

The interaction between hydrogen and various high temperature protonic conductors (HTPC) has not been clearly understood due to poor densification and unreacted secondary phases. the melt-processing technique is used in producing fully dense simple SrCe(0.9)Y (0.10) O(3-delta) and complex Sr3Ca(1+x)Nb(2+x)O(9-delta) perovskites that can not be achieved by solid-state sintering. the possibilities of ion beam analysis have been investigated to quantify hydrogen distribution in HTPC perovskites subjected to water heat treatment. Nuclear microprobe technique is based on the interactions of a focused ion beam of MeV light ions (H-1, H-2, He-3, He-4,.) with the sample to be analyzed to determine local elemental concentrations at the cubic micrometer scale, the elastic recoil detection analysis technique (ERDA) has been carried out using He-4(+) microbeams and detecting the resulting recoil protons. Mappings of longitudinal sections of water treated SrCeO3 and Sr(Ca(1/3)Nb(2/3))O3 perovskites have been achieved, the water treatment strongly alters the surface of simple SrCe(0.9)Y(0.10)O(3-delta) perovskite. From Rutherford Back Scattering measurements (RBS), both Ce depletion and surface re-deposition is evidenced. the ERDA investigations on water treated Sr3Ca(1+x)Nb(2+x)O(9-delta) perovskite did not exhibit any spatial difference for the hydrogen incorporation from the surface to the centre. the amount of hydrogen incorporation for Sr3Ca(1+x)Nb(2+x)O(9-delta) was low and required further development of two less conventional techniques, ERDA in forward geometry and forward elastic diffusion H-1(p,p) H-1 with coincidence detection.

Berger, Pascal↗
NASA NTRS2007

High Temperature Protonic Conductors

High Temperature Protonic Conductors (HTPC) with the perovskite structure are envisioned for electrochemical membrane applications such as H2 separation, H2 sensors and fuel cells. Successive membrane commercialization is dependent upon addressing issues with H2 permeation rate and environmental stability with CO2 and H2O. HTPC membranes are conventionally fabricated by solid-state sintering. Grain boundaries and the presence of intergranular second phases reduce the proton mobility by orders of magnitude than the bulk crystalline grain. To enhanced protonic mobility, alternative processing routes were evaluated. A laser melt modulation (LMM) process was utilized to fabricate bulk samples, while pulsed laser deposition (PLD) was utilized to fabricate thin film membranes . Sr3Ca(1+x)Nb(2-x)O9 and SrCe(1-x)Y(x)O3 bulk samples were fabricated by LMM. Thin film BaCe(0.85)Y(0.15)O3 membranes were fabricated by PLD on porous substrates. Electron microscopy with chemical mapping was done to characterize the resultant microstructures. High temperature protonic conduction was measured by impedance spectroscopy in wet air or H2 environments. The results demonstrate the advantage of thin film membranes to thick membranes but also reveal the negative impact of defects or nanoscale domains on protonic conductivity.

Dynys, Fred↗